[clang] [llvm] [DebugInfo] Update DIBuilder insertion to take InsertPosition (PR #126059)

[Jeremy Morse via cfe-commits]

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@@ -1708,19 +1706,9 @@ static void insertDbgValueOrDbgVariableRecord(DIBuilder &Builder, Value *DV,
 
 static void insertDbgValueOrDbgVariableRecordAfter(
     DIBuilder &Builder, Value *DV, DILocalVariable *DIVar, DIExpression *DIExpr,
-    const DebugLoc &NewLoc, BasicBlock::iterator Instr) {
-  if (!UseNewDbgInfoFormat) {
-    auto DbgVal = Builder.insertDbgValueIntrinsic(DV, DIVar, DIExpr, NewLoc,
-                                                  (Instruction *)nullptr);
-    cast<Instruction *>(DbgVal)->insertAfter(Instr);
-  } else {
-    // RemoveDIs: if we're using the new debug-info format, allocate a
-    // DbgVariableRecord directly instead of a dbg.value intrinsic.
-    ValueAsMetadata *DVAM = ValueAsMetadata::get(DV);
-    DbgVariableRecord *DV =
-        new DbgVariableRecord(DVAM, DIVar, DIExpr, NewLoc.get());
-    Instr->getParent()->insertDbgRecordAfter(DV, &*Instr);
-  }
+    const DebugLoc &NewLoc, Instruction *Instr) {
+  insertDbgValueOrDbgVariableRecord(Builder, DV, DIVar, DIExpr, NewLoc,
+                                    std::next(Instr->getIterator()));
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jmorse wrote:

I endorse the amount of red here; I believe we need to call `setHeadBit(true)` on the next-iterator though, to ensure that in sequences such as:

    inst
    #dbg_value
    inst2

Inserting after `inst` will come before the pre-existing dbg_value, rather than after it.

https://github.com/llvm/llvm-project/pull/126059